Ashba tweeted after that tweet was posted that he was in the middle of hanging out with Axl and they were buying guns together, so it's not him. Maybe the lawsuit is taking a turn for the ugly or something?
The official GnR twitter says that they haven't had any confirmation from Axl yet:
We are looking into the tweet from the @AxlRose twitter account. Please keep with us here for official word.
..So there's a chance that Axl's account got hacked or something.